The Houston Ship Channel (HSC) consists of approximately 65 miles of improved deep-draft channels. The present channel is 400 ft wide and 40 ft deep at mean low tide for most of the channel distance. The project design calls for the channel to be improved in two phases. The Phase I channel is to be 530 ft wide and 45 ft deep, and the Phase II channel is to be 600 ft wide and 50 ft deep. The US Army Engineer Waterways Experiment Station (WES) conducted a real-time ship simulation study of the project area to determine the optimum channel. The HSC is designed for two-way deep-draft traffic. The capability of large loaded vessels to meet and pass determines the safe channel width. In the existing highly restricted channel, both bank and ship interaction effects are significant factors in conducting bow-on meeting and passing maneuvers. Prototype data and data from a physical model were used to provide guidance in simulating this maneuver.